Wireless services available to mobile subscribers have rapidly evolved in recent years from providing voice-only communications to including high-speed data and location based services (LBS). Mobile subscribers are now able to take advantage of a plethora of offered wireless services to browse the web, download music and video files, communicate via email, locate relatives, receive geographical guidance based on subscriber location, and obtain directions.
However, the rapid transition to a multi-service based mobile environment by wireless service providers operating heterogeneous network technologies resulted in networks based on various standards that have their own migration timelines and paths. For example, basic data and location based services that fall outside of the FCC-mandated schedule (e.g., street guidance services) are typically implemented on a carrier-specific schedule. This results in a non-uniform availability of various services across different mobile networks and platforms and significantly complicates access to various wireless services during roaming.
Traditionally, a Preferred Roaming List (PRL) has been used by the wireless operators to control the availability of roaming networks for a mobile subscriber. However, traditional PRL-controlled roaming schemes are not conducive to taking into account a large number of different wireless service combinations that may be offered among all roaming partners, which may result in failed service initiations on roaming networks that do not provide the requested service. Additionally, traditional PRL-controlled roaming schemes lack an efficient way to take into account multiple factors that affect selecting the most optimum roaming network on which to initiate the requested wireless service.
For instance, a roaming scheme described in U.S. Publication No. 2008/0139241 to Kiymoto (hereinafter “Kiymoto”) assigns each call type an access technology preference for initiation of outgoing calls. For example, the mobile gives priority to systems complying with an EVDO access technology type for “videophone” call initiations. However, the roaming scheme in Kiymoto operates on an access technology level and does not address a way to take into account multiple service combinations specific to each roaming network provider. Since priority is assigned on access technology basis, the roaming scheme in Kiymoto further lacks the ability to prioritize system selection based on service parameters that differ among specific roaming network providers.
U.S. Publication No. 2007/0123231 to Kim (hereinafter “Kim”) describes a mobile having multiple PRL versions, thereby allowing an operator to restrict unauthorized access to an “enhanced” system. Specifically, if the mobile exceeds a predetermined number of failed attempts to access an “enhanced” system, the “enhanced” PRL is replaced with a “basic” PRL and access to the “enhanced” system is restricted. However, Kim does not address a way to take into account multiple wireless services offered by each roaming network provider. Furthermore, Kim does not address taking into account multiple factors that affect selecting the most optimum roaming service provider on which to initiate the requested wireless service.
U.S. Publication No. 2008/0132229 to Oommen et al. (hereinafter “Oommen”) describes a mobile unit that receives a custom PRL based on the type of access technology (e.g., CDMA, GSM) on which the mobile is attempting to roam. However, Oommen does not describe a service-specific PRL and does not address a way to take into account multiple wireless services offered by various roaming network providers. Furthermore, Oommen does not address taking into account multiple factors that affect selecting the most optimum roaming network provider on which to initiate the requested wireless service.
U.S. Pat. No. 5,983,092 to Whinnett et al. (hereinafter “Whinnett”) does not rely on PRL-based roaming and, as a result, requires additional messaging between the mobile and a plurality of candidate networks to identify a network capable of providing the requested service.
Finally, PCT Publication No. WO2005/041611 to Babbar et al. (hereinafter “Babbar”) similarly does not rely on PRL-based roaming and requires user interaction to manually select an “access string,” via a user interface, describing the type of service to be initiated.
Therefore, a need exists for an efficient way to facilitate home networks that utilize PRL-based roaming to take into account a significant number of various wireless service combinations offered by individual roaming partners, as well as to take into account multiple factors affecting the selection of an optimum roaming network that provides the desired service or service mix.